KR20060041751A - Imaging composition and method - Google Patents

Abstract

Imaging compositions, products, and imaging methods are disclosed. Imaging compositions are energy sensitive and affect color or hue upon application to a sufficient amount of energy in the composition. The imaging composition is coated onto the product to form an energy sensitive product that can be used to mark the workpiece.

Description

Imaging composition and method             

1 is a cross-sectional view of an adhesive article containing an imaging composition.

FIG. 2 is a photofugitive response picture with a composition dried on a polymer film after selective application of a laser beam. FIG.

3 is a phototropic response picture of the composition dried on a polymer film after selective application of a laser beam.

The present invention relates to imaging compositions and methods. More specifically, the present invention relates to stable imaging compositions suitable for application on a substrate to form a product and methods of using the product.

There are many compositions and methods used to mark images by forming images on the substrate in various industries. Some of these industries include the paper industry, packaging industry, painting industry, medical industry, dental industry, electronics industry, textile industry, aviation, shipping and automotive industries, and imaging technology. Imaging or marking is typically used to identify a product, such as the manufacturer's name or logo, serial number or lot number, tissue type, or for deployment purposes in the manufacture of semiconductor wafers, air ships, marine shipping vessels and earth vehicles. Can be.

Marking is also used to check products, photoresists, soldermasks, printing plates and other photopolymer products. For example, U.S. 5,744,280 discloses photoimageable compositions capable of forming so-called monochrome and multichrome images, which have contrast image properties. Photoimaging compositions include photoacidizers, photosensitizers, photodeactivation compounds and deuterated leuco compounds. The leuco compound is an aminotriarylmethine compound or related compound in which at least 60% is deuterated by deuterium mixing in place of the hydrido aminotriaryl-methine to which the methane (center) carbon atom corresponds. This patent claims that deuterated leuco compounds increase contrast imaging as opposed to the corresponding hydrido leuco compounds. The phototropic reaction is induced when the photoimaging composition is exposed to actinic radiation.

The display of information on the label, the logo fixing on the fabric, or other information such as company name, part or serial number or lot number, or information stamping such as die location in the semiconductor device can be acted by direct printing. Printing may be performed by pad printing or screen printing. Pad printing has the advantage of printing curved surfaces due to the expandability of the pad, but has a disadvantage of making fine patterns precise. Screen printing is difficult to obtain fine patterns precisely with the limited mesh size of the screen. In addition to poor precision, printing is in no way suitable for applications requiring real-time processing, since printing requires the production of plates for the desired patterns each time or takes time to set the printing conditions.

Thus, marking by printing has recently been replaced by ink jet marking. While ink jet marking meets the requirements for speed and real-time processing that many conventional printing systems did not, the ink used, which is ejected from the nozzle under pressure, is strictly defined. If it does not exactly match the specification, the ink sometimes causes nozzle blockage and the rejection rate is increased.

In order to overcome this problem, laser marking has recently attracted attention as a high speed and high efficiency marking method and has already been implemented in some industries. Many laser marking techniques involve irradiating only the necessary area of the substrate with laser light to denature or remove the irradiated area or irradiating the coated substrate with laser light to remove the irradiated coating layer. Contrast is created between non-irradiated sites.

The use of laser marking products such as semiconductor chips is a fast and economic means of display. However, there are disadvantages associated with the latest laser marking techniques in which the surface is burned to achieve the desired marking. For example, marking burned off the surface by a laser can only be seen at a selected angle of incidence on the light source. In addition, oil or other contaminants deposited on the product surface after marking may obscure or even block the laser marking. In addition, since the laser burns the actual workpiece surface, for bare die marking, the associated combustion can damage the underlying structure or internal circuitry or damage by increasing the internal die temperature beyond the permissible limits. You can. Moreover, if the manufactured part is not made of a laser reactive material, the laser reactive coating applied to the part surface may take several hours to add cost and cure.

Alternatively, a laser projector can be used to project the image onto the surface. These projectors are used to help fix the workpiece of the workpiece. Some systems are designed to project three-dimensional images on surfaces with outlines, not on flat surfaces. The projected image is used as a pattern for manufacturing a product and is used to scan an image of the desired position of the ply on a predetermined ply. One example of such use is in the manufacture of leather goods, truss, and aircraft fuselage. Laser projectors are also used for template positioning or paint masks during aircraft paint.

The use of a scanned laser image to provide marking of where to designate or arrange the workpiece for drilling, for forming an outline for drawing a logo or picture, or for arranging to bond segments of a marine vessel is a work piece. Extreme accuracy is required to calibrate the position of the laser projector with respect to the plane. Typically six reference points are needed for precision enough to align the machined parts. The reflector or sensor is located in the proximity of where the ply will be located. Since the reference point is in a fixed position relative to the workpiece and the laser, it also knows where the laser is relative to the workpiece. Typically, workers can indicate where the laser beam image contacts the workpiece with a marker or masking tape that defines the laser image. This method is tedious and can block the beam when the operator's hand moves in front of the beam making the masking. Therefore, misalignment may occur.

Another problem associated with laser marking is the danger of damaging the operator's eyes. Many lasers that can be used for marking can damage the worker's retina. In general, lasers generating energy in excess of 5 mW are harmful to the operator.

Therefore, there is a need for improved imaging compositions and methods of marking workpieces.

Summary of the Invention

The article includes an imaging composition having one or more sensitizers in an amount sufficient to change the color or hue of the composition upon application of energy at a power of 5 mW or less.

In another embodiment, the article comprises an imaging composition having one or more sensitizers in an amount sufficient to change the color or hue of the composition upon application of energy at a power of 5 mW or less, the imaging composition coating one side of the article and opposing Cotton includes an adhesive.

In another embodiment, the article comprises an imaging composition having one or more sensitizers in an amount sufficient to change the color or hue of the composition upon application of energy at a power of 5 mW or less, the imaging composition comprising one side of the polymer base. The opposite side of the coating and the polymer base comprises an adhesive having an adhesive release coating, the protective layer covering the imaging composition.

Imaging compositions may include binder polymers, diluents, plasticizers, flow agents, accelerators, adhesion promoters, organic acids, surfactants, chain transfer agents, thickeners, rheology improvers, and other optional components that make the imaging composition suitable for the desired notation and substrate. Can be. The article having the imaging composition can then be applied to a suitable workpiece to form the image used to make the article.

In another embodiment, the imaging method provides an imaging composition having one or more sensitizers in an amount sufficient to change the color or hue of the composition upon application of energy at a power of 5 mW or less; Applying the imaging composition to a substrate to form a product; Applying the product to the workpiece; Applying energy to the imaging composition at a power of 5 mW or less to change color or hue. Such products and methods are fast and efficient means of changing the color or color tone of a workpiece, placing a pattern on a workpiece such as an aeronautical vessel, a marine vessel, and a earth vehicle, or forming an image on a textile.

A portion of the imaging composition may be removed with a suitable developer or stripper before or after performing further processing on the work piece. If the product has a peelable adhesive, unwanted portions can be peeled off from the workpiece.

The images can be used as marks or indicators, for example, to drill holes to tie the connecting parts together, to draft them for displaying a logo or picture on an airplane, or to align segments of ship parts. Since the product can be quickly applied to the workpiece and the image can be formed quickly by applying energy to form color or tonal contrast, the operator no longer marks the workpiece with a portable marker or tape when manufacturing the product. There is no need to adjoin the image. Thus, the light blocking problem caused by the worker moving by hand and the slow and boring process of applying the mark by the worker using a portable marker or a piece of tape are excluded. In addition, the low energy power used to change the color or color tone prevents, or at least reduces, the risk of damaging the operator's eyes.

Reducing errors by humans increases the accuracy of marking. This is important when the mark is used to specify the alignment of parts, such as aeronautical vessels, marine vessels or earth vehicles, whose accuracy in manufacturing is critical to the reliability and safe operation of the machine.

The imaging composition may be applied to the substrate by methods such as spray coating, roller coating, dipping, ink jetting, brosing, or other suitable method. Energy sources that apply sufficient amounts of energy to change color or hue include, but are not limited to, devices that emit lasers, infrared rays, and ultraviolet rays. Conventional devices can be used, so there is no need to use new specialized devices to use the products and methods. In addition, the non-selective single coating application of the product onto the workpiece, followed by rapid application of energy to change color or hue, makes the product suitable for assembly lines. Thus, products are provided that are more efficient than many conventional alignment and imaging processes.

The following abbreviations used throughout this specification have the following meanings: ° C = degrees Celsius; IR = infrared; UV = ultraviolet; g = grams; Mg = milligrams; l = liter; Ml = milliliters; wt% = weight percent; erg = 1 dyne cm = 10 ^-7 joules; J = joule; mJ = milli Joules; nm = nanometers; = 10 ^-9 meters; Cm = centimeters; Mm = millimeters; W = watts = 1 joule / second; mW = milliwatts; ns = nanoseconds; μsec = microseconds; Hz = hertz; KV = kilovolts.

The terms "polymer" and "copolymer" are used interchangeably throughout this specification. "Chemical radiation" means radiation from light that induces chemical change. "Photofugitive response" means that the application of energy makes the coloring material fade or brighter. "Phototropic response" means that energy application darkens the material. "Tint change" means that the color fades or becomes darker. "(Meth) acrylate" includes methacrylate and acrylate, and "(meth) acrylic acid" includes methacrylic acid and acrylic acid. "Diluent" means a carrier or excipient such as a solvent or a solid filler.

Unless stated otherwise, all percentages are by weight and based on dry weight or weight excluding solvent. All numerical ranges are inclusive and can be combined in any order, but logically these numerical ranges must add up to 100%.

The article includes an imaging composition having one or more sensitizers in an amount sufficient to change the color or hue of the composition upon application of energy at a power of 5 mW or less. The imaging composition may be applied to a substrate to form a product. After applying the product to the workpiece, a sufficient amount of energy is applied to change the color or color tone of the entire product or to form a patterned image on the product. For example, a product having an imaging composition is selectively applied to the workpiece and then energy is applied to change the color or hue to form a patterned image on the product. Alternatively, after covering the entire workpiece with the article having the imaging composition, energy can be selectively applied to change the color or hue to form a patterned image on the article. After image formation on the workpiece, further processing can be performed to form the product as described below.

A sensitizer used in the composition is a compound that is activated by energy to change the color or hue, or activate to change the color or hue of one or more other compounds. The imaging composition includes one or more photosensitizers that are sensitive to visible light and can be activated with energy of up to 5 mW of power. Generally, such sensitizers are included in an amount of 0.005 to 10% by weight, or for example 0.05 to 5% by weight, or 0.1 to 1% by weight relative to the imaging composition.

A sensitizer that is activated in the visible range is typically activated at a wavelength above 300 nm but below 600 nm, or for example 350 to 550 nm, or 400 to 535 nm. Such sensitizers are conjugated compounds based on cyclopentanone such as cyclopentanone, 2,5-bis- [4- (diethylamino) phenyl] methylene]-, cyclopentanone, 2,5-bis- [2,3,6,7-tetrahydro-1H, 5H-benzo [i, j] quinolizine-9-yl) methylene]-, cyclopentanone, 2,5-bis- [4- (diethyl Amino) -2-methylphenyl] methylene]-, cyclopentanone, including but not limited to. Such cyclopentanone can be prepared from cyclic ketones and tricyclic aminoaldehydes by methods known in the art.

Examples of suitable conjugated cyclopentanones have Formula 1 as follows:

Where

p and q are independently 0 or 1,

r is 2 or 3,

R ₁ is independently hydrogen, linear or branched (C ₁ -C ₁₀ ) aliphatic, or linear or branched (C ₁ -C ₁₀ ) alkoxy, typically R ₁ is independently hydrogen, methyl or methoxy,

R ₂ is independently hydrogen, linear or branched (C ₁ -C ₁₀ ) aliphatic, (C ₅ -C ₇ ) ring, for example an alicyclic ring, phenyl, alkaryl, linear or branched (C ₁ -C ₁₀ ) Hydroxyalkyl, linear or branched chain hydroxy terminating ether, for example-(CH ₂ ) _v -O- (CHR ₃ ) _w -OH, where v is an integer from 2 to 4 and w is from 1 to Is an integer of 4),

R ₃ is hydrogen or methyl,

The carbon of each R ₂ is a 5 to 7 membered ring having nitrogen together or a 5 to 7 membered ring having other heteroatoms selected from nitrogen and oxygen, sulfur and a second nitrogen.

The sensitizer may be activated at a power of 5 mW or less.

Other sensitizers that are activated in the visible range include N-alkylamino aryl ketones such as bis (9-judolidyl ketone), bis (N-ethyl-1,2,3,4-tetrahydro-6-qui Noyl) ketone and p-methoxyphenyl- (N-ethyl-1,2,3,4-tetrahydro-6-quinolyl) ketone; Visible light absorbing dyes prepared by base catalyzed condensation of an aldehyde or dimethinehemicyanine with the corresponding ketone; Visible light absorbing squarylium compounds; 1,3-dihydro-1-oxo-2H-indene derivatives; Coumarin-based dyes such as ketocoumarin and 3,3'-carbonyl bis (7-diethylaminocoumarin); Halogenated titanocene compounds, for example bis (eta.5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) phenyl) titanium; And compounds derived from aryl ketones and p-dialkylaminoarylaldehydes. Examples of further sensitizers include light absorber materials based on fluorescein type dyes and triarylmethane nuclei. Such compounds include Eosin, Eosin B and Rose Bengal. Another suitable compound is Erythrosin B. Methods of making such sensitizers are known in the art and many are commercially available. Typically such visible light sensitizers are used in amounts of 0.05 to 2% by weight, or for example 0.25 to 1% or 0.1 to 0.5% by weight relative to the composition.

Optionally, the imaging composition may include one or more photosensitizers that are activated by UV light. Such photosensitizers are typically activated at wavelengths above 10 nm but below 300 nm, or for example between 50 and 250 nm, or between 100 and 200 nm. Such UV-activated photosensitizers are polymer photoresists with a weight average molecular weight of 10,000 to 300,000, for example 1- [4- (dimethylamino) phenyl] -1- (4-methoxyphenyl) methanone, 1- [4- (dimethylamino ) Phenyl] -1- (4-hydroxyphenyl) methanone and 1- [4- (dimethylamino) phenyl] -1- [4- (2-hydroxyethoxy) phenyl] methanone; Free base of ketone imine dye; Amino derivatives of triarylmethane dyes; Amino derivatives of xanthene dyes; Amino derivatives of acridine dyes; Methine dyes; And polymethine dyes, but are not limited thereto. Methods of preparing these compounds are known in the art. Typically, such UV activated sensitizers are used in the composition in an amount of 0.05 to 1% by weight, or for example 0.1 to 0.5% by weight relative to the composition.

Optionally, the imaging composition may include one or more photosensitizers that are activated by IR light. Such photosensitizers are typically activated at wavelengths above 600 nm but below 1,000 nm, or for example between 700 and 900 nm, or between 750 and 850 nm. Such IR activated photosensitizers include, but are not limited to, infrared squarylium dyes and carbocyanine dyes. Methods of preparing these compounds are known in the art and can be prepared by the methods disclosed in the literature. Typically, such UV activated sensitizers are used in amounts of 0.05 to 1% by weight, or for example 0.5 to 2% by weight, or 0.1 to 1% by weight relative to the composition.

Compounds that can act as reducing agents include one or more quinone compounds, for example pyrenquinones such as 1,6-pyrenquinone and 1,8-pyrenquinone; 9,10-anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, octamethylanthraquinone, 1,4-naphtho Quinone, 9,10-phenanthrequinone, 1,2-benzaanthraquinone, 2,3-benzanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dichloronaphthoquinone, 1,4 -Dimethylanthraquinone, 2,3-dimethylanthraquinone, sodium salt of anthraquinone alpha-sulfonic acid, 3-chloro-2-methylanthraquinone, retenquinone, 7,8,9,10-tetrahydronaphthacequinone and 1,2,3,4-tetrahydrobenz (a) anthracene-7,12-dione is included, but is not limited thereto.

Other compounds that can act as reducing agents include, but are not limited to, acyl esters of triethanolamine of the formula:

Where

R is 0 to 99% of C ₁ -C ₄ alkyl and 3,3 ′, 3 ″ -nitrilotripropionic acid or C ₁ -C ₄ alkyl ester of nitrilotriacetic acid.

Examples of such acyl esters of triethanolamine include triethanolamine triacetate and dibenzylethanolamine acetate.

One or more reducing agents may be used in the imaging composition to provide the desired color or hue change. Typically, one or more quinones may be used with acyl esters of one or more triethanolamines to achieve the desired reducing agent action effect. The reducing agent is used in an amount of 0.05 to 50% by weight, or for example 0.1 to 40% by weight, or 0.5 to 35% by weight relative to the composition.

Chain transfer agents can be used in the imaging composition. Such chain transfer agents can act as promoters. Chain transfer agents or accelerators increase the rate of change of color or hue after exposure to energy. Any compound that promotes the rate of color or hue change can be used. Promoter is included in the composition in an amount of 0.01 to 25% by weight, or for example 0.5 to 10% by weight. Examples of suitable promoters include onium salts and amines.

Suitable onium salts are onium salts in which the onium cation is iodonium or sulfonium, for example onium salts of arylsulfonyloxybenzenesulfonate anions, phosphonium, oxysulfonium, oxulfonium, sulfoxonium, ammonium, Diazonium, celononium, arsonium and N-substituted N-heterocyclic onium, wherein N is substituted with substituted or unsubstituted saturated or unsaturated alkyl or aryl groups, but is not limited thereto. .

The anions of the onium salts are for example chlorides or non-nucleophilic anions such as tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate, hexafluoroantimonate, triflate, tetrakis- (pentafluorophenyl ) Borate, pentafluoroethyl sulfonate, p-methylbenzyl sulfonate, ethylsulfonate, trifluoromethyl acetate and pentafluoroethyl acetate.

Examples of typical onium salts are, for example, diphenyl iodonium chloride, diphenyl iodonium hexafluorophosphate, diphenyl iodonium hexafluoroantimonate, 4,4'-dicumyliodonium chloride, 4 , 4'-dicumyliodonium hexafluorophosphate, N-methoxy-a-picolinium-p-toluene sulfonate, 4-methoxybenzene-diazonium tetrafluoroborate, 4,4'-bis -Dodecylphenyliodonium hexafluoro phosphate, 2-cyano-triphenylphosphonium chloride, bis- [4-diphenylsulfonionphenyl] sulfide-bis-hexafluoro phosphate, bis-4-dodecyl Phenyliodonium hexafluoroantimonate and triphenylsulfonium hexafluoroantimonate.

Suitable amines are primary, secondary and tertiary amines such as methylamine, diethylamine, triethylamine, heterocyclic amines such as pyridine and piperidine, aromatic amines such as aniline, quaternary ammonium halides, For example tetraethylammonium fluoride, and quaternary ammonium hydroxides such as tetraethylammonium hydroxide. Triethanolamine of the formula (2) also has promoter activity in addition to being used as a reducing agent.

Other compounds, such as color formers, can be used in the imaging composition. Such color formers include, but are not limited to, leuco type compounds. Such color formers also contribute to color or hue changes. Suitable leuco type compounds include aminotriarylmethane, aminoxanthene, aminothioxanthene, amino-9,10-dihydroacridine, aminophenoxazine, aminophenothiazine, aminodihydrophenazine, antinodiphenyl Methine, leuco indamine, aminohydrocinnamic acid, for example cyanoethane and leuco methine, hydrazine, leuco indigoid dye, amino-2,3-dihydroanthraquinone, tetrahalo-p, p'-biphenol , 2- (p-hydroxyphenyl) -4,5-diphenylimidazole and phenethylaniline. These compounds are included in the composition in an amount of 0.1 to 5% by weight, or for example 0.25 to 3% by weight, or 0.5 to 2% by weight.

When leuco type compounds are used in the composition, one or more oxidants are typically included. Compounds that can act as oxidizing agents are hexaarylbiimidazole compounds, for example 2,4,5,2 ', 4', 5'-hexaphenylbiimidazole, 2,2 ', 5-tris (2-chloro Phenyl) -4- (3,4-dimethoxyphenyl) -4,5-diphenylbiimidazole (and isomers), 2,2'-bis (2-ethoxyphenyl) -4,4 ', 5, 5'-tetraphenyl-1,1'-bi-1H-imidazole and 2,2'-di-1-naphthalenyl-4,4 ', 5,5'-tetraphenyl-1'-bi-1H Include, but are not limited to, imidazole. Other suitable compounds include halogenated compounds having up to 1 hydrogen attached and having a bond dissociation energy that produces a first halogen with at least 40 kilocalories per mole of free radicals; Sulfonyl halides of the formula R'-SO ₂ -X, wherein R 'is alkyl, alkenyl, cycloalkyl, aryl, alkaryl or aralkyl, and X is chlorine or bromine; Sulfenyl halides of the formula R "-S-X ', wherein R" and X' have the same meaning as said R 'and X; Tetraaryl hydrazine, benzothiazolyl disulfide, polymetharylaldehyde, alkylidene 2,5-cyclohexadien-1-one, azobenzyl, nitroso, alkyl (T1), peroxide and haloamine It is not limited only. These compounds are included in the composition in an amount of 0.25 to 10% by weight, or for example 0.5 to 5% by weight, or 1 to 3% by weight. Methods for preparing these compounds are known and many are commercially available.

Film formers can be used in the imaging composition to act as a binder for the composition. Such film formers may be used in the formulation of the composition under conditions that do not adversely interfere with the desired color or hue change. The film former is included in an amount of 10 to 90% by weight, or for example 15 to 70% by weight, or 25 to 60% by weight relative to the composition. Typically, the film former is derived from a mixture of acid functional monomers and non-acid functional monomers. Acid and non-acid functional monomers are combined to form copolymers having an acid value of at least 80 or for example 150 to 250. Examples of suitable acid application monomers include (meth) acrylic acid, maleic acid, fumaric acid, citraconic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-hydroxyethyl acrylol phosphate, 2-hydroxypropyl acrylol Phosphates and 2-hydroxy-alpha-acrylol phosphate are included, but are not limited to these.

Examples of suitable non-acid functional monomers include esters of (meth) acrylic acid, for example methyl acrylate, 2-ethyl hexyl acrylate, n-butyl acrylate, n-hexyl acrylate, methyl methacrylate, hydroxyl ethyl Acrylate, butyl methacrylate, octyl acrylate, 2-ethoxy ethyl methacrylate, t-butyl acrylate, 1,5-pentanediol diacrylate, N, N-diphenylaminoethyl acrylate, ethylene glycol Diacrylate, 1,3-propanediol diacrylate, decamethylene glycol diacrylate, decamethylene glycol dimethacrylate, 1,4-cyclohexanediol diacrylate, 2,2-dimethylol propane diacrylate , Glycerol diacrylate, tripropylene glycol diacrylate, glycerol triacrylate, 2,2-di (p-hydroxyphenyl) propane dimethacrylate, t Ethylene glycol diacrylate, polyoxyethyl-2,2-di (p-hydroxyphenyl) propane dimethacrylate, triethylene glycol dimethacrylate, polyoxypropyltrimethylol propane triacrylate, ethylene glycol dimetha Acrylate, butylene glycol dimethacrylate, 1,3-propanediol dimethacrylate, 1,2,4-butanetriol trimethacrylate, 2,2,4-trimethyl-1,3-pentaerythritol Dimethacrylate, pentaerythritol trimethacrylate, 1-phenyl ethylene-1,2-dimethacrylate, pentaerythritol tetramethacrylate, trimethylol propane trimethacrylate, 1,5-pentanediol dimethacrylate Rate; Styrene and substituted styrenes such as 2-methyl styrene and vinyl toluene and vinyl esters such as vinyl acrylate and vinyl methacrylate.

Other suitable polymers include, but are not limited to, nonionic polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyl-ethylcellulose and hydroxyethylpropyl methylcellulose.

Optionally, one or more plasticizers can be included in the composition. Any suitable plasticizer can be used. The plasticizer may be included in the composition in an amount of 0.5 to 15% by weight, or for example 1 to 10% by weight. Examples of suitable plasticizers include phthalates such as dibutylphthalate, diheptylphthalate, dioctylphthalate and diallyl phthalate, glycols such as polyethylene glycol and polypropylene glycol, glycol esters such as triethylene glycol diacetate, Tetraethylene glycol diacetate and dipropylene glycol dibenzoate, phosphate esters such as tricresyl phosphate, triphenyl phosphate, amides such as p-toluenesulfonamide, benzenesulfonamide, Nn-butylacetonamide, aliphatic Dibasic acid esters such as diisobutyl-adipate, dioctyl adipate, dimethyl sebacate, dioctyl azelate, dibutyl maleate, triethyl citrate, tri-n-butylacetyl citrate, butyllau Latex, dioctyl-4,5-diepoxycyclohexane-1,2-dicarboxyle And bit, including, glycerin triacetyl ester, and is not limited only thereto.

Optionally, one or more flow agents may be included in the composition. Flow agents are compounds that provide a smooth and flat coating on a substrate. Glidants may be included in the composition in an amount of 0.05 to 5% by weight, or for example 0.1 to 2% by weight. Suitable flow agents include, but are not limited to, copolymers of alkylacrylates. Examples of such alkylacrylates are copolymers of ethyl acrylate and 2-ethylhexyl acrylate.

Optionally, one or more organic acids can be included in the composition. The organic acid may be used in the composition in an amount of 0.01 to 5% by weight, or for example 0.5 to 2% by weight. Examples of suitable organic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid capronic acid, caprylic acid, capric acid, lauric acid, phenylacetic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, 2-ethylhexane Acids, isobutyric acid, 2-methylbutyric acid, 2-propylheptanoic acid, 2-phenylpropionic acid, 2- (p-isobutylphenyl) propionic acid and 2- (6-methoxy-2-naphthyl) propionic acid, It is not limited only to this.

Optionally, one or more surfactants may be used in the composition. The surfactant may be included in the composition in an amount of 0.5 to 10% by weight, or for example 1 to 5% by weight. Suitable surfactants include nonionic, ionic and amphoteric surfactants. Examples of suitable nonionic surfactants include polyethylene oxide ethers, derivatives of polyethylene oxide, aromatic ethoxylates, acetylenic ethylene oxide and block copolymers of ethylene oxide and propylene oxide. Examples of suitable ionic surfactants include alkali metal, alkaline earth metal, ammonium and alkanol ammonium salts of alkyl sulfates, alkyl ethoxy sulfates and alkyl benzene sulfonates. Examples of suitable amphoteric surfactants include derivatives of aliphatic secondary and tertiary amines, wherein the aliphatic radicals can be straight or branched, one or the other aliphatic substituents containing 8 to 18 carbon atoms and one being carboxy, sulfo And anionic water-soluble groups such as sulfate, phosphate or phosphono. Particular examples of such surfactants are 3-dodecylaminopropionate and sodium 3-dodecylaminopropane sulfonate.

Optionally, thickeners can also be used in the compositions. Any suitable thickener can be used. Examples of suitable thickeners are compound thickeners. Examples of such thickeners include polyurethanes, hydrophobically modified alkali soluble emulsions, hydrophobically modified hydroxyethyl cellulose and hydrophobically modified polyacrylamides. Examples of suitable polyurethane thickeners are low molecular weight polyurethanes having at least three hydrophobic groups interconnected by hydrophilic polyether groups. The molecular weight of such thickeners is 10,000 to 200,000. Thickeners are included in the compositions in amounts of 0.5 to 10% by weight, or for example 1 to 5% by weight.

Fluidity improvers can be included in conventional amounts. Typically, the rheology improving agent is used in the composition in an amount of 0.5 to 20% by weight, or for example 5 to 15% by weight. Examples of rheology improvers include vinyl aromatic polymers and acrylic polymers.

Diluents are included in the composition as excipients or carriers for other ingredients. Diluents are added as needed. Solid diluents or fillers are typically added to bring the dry weight of the composition to 100% by weight. An example of a solid diluent is cellulose. Liquid diluents or solvents are used to make the active ingredients of the imaging composition into solutions, suspensions or emulsions. The solvent can be aqueous, organic or mixtures thereof. Examples of organic solvents are alcohols such as methyl, ethyl, and isopropyl alcohol, propanol, diisopropyl ether, diethylene glycol dimethyl ether, 1,4-dioxane, tetrahydrofuran or 1,2-dimethoxy propane And esters such as butylollactone, ethylene glycol carbonate and propylene glycol carbonate, ether esters such as methoxyethyl acetate, ethoxyethyl acetate, 1-methoxypropyl-2-acetate, 2-methoxypropyl -1-acetate, 1-ethoxypropyl-2-acetate and 2-ethoxypropyl-1-acetate, ketones such as acetone and methylethyl ketone, nitriles such as acetonitrile, propionitrile and Methoxypropionitrile, sulfones such as sulfolane, dimethylsulfone and diethylsulfone, and phosphoric acid esters such as trimethyl phosphate and triethyl phosphate.

The imaging composition may be in concentrated form. In such concentrates, the solids content may be 80 to 98% by weight, or for example 85 to 95% by weight. The concentrate may be diluted with water, one or more organic solvents, or a mixture of water and one or more organic solvents. The concentrate may be diluted to a solids content of less than 5 to 80 weight percent, or for example 10 to 70 weight percent, or 20 to 60 weight percent.

The imaging composition may be applied to the substrate by spray coating, roller coating, brosing or dipping. A sufficient amount of heat may be applied from an air drying or warm air dryer or oven to remove any solvent or residual solvent to achieve adhesion between the composition and the substrate.

Optionally, one or more adhesion promoters may be included in the imaging composition to improve adhesion between the imaging composition and the substrate. Such adhesion promoters may be included in the imaging composition in amounts of 0.5 to 10 weight percent, or for example 1 to 5 weight percent. Examples of such red chopstick enhancers include acrylamido hydroxy acetic acid (hydrated and anhydrous), biacrylamido acetic acid, 3-acrylamido-3-methylbutanoic acid and mixtures thereof.

The imaging composition is applied to the film substrate with an adhesive applied to the opposite side on which the imaging composition is coated. One example of such a film substrate is an adhesive tape. The imaging composition is coated on one side of the film with a thickness of 0.5 nm to 10 mm, or for example 1 to 5 mm. Coating can be carried out by conventional methods such as spray coating, roller coating, dipping or brosing. The adhesive is coated on the opposite side of the substrate to a thickness of 5 to 50 μm, or for example 10 to 25 μm.

Any suitable adhesive can be used on the substrate. The adhesive can be a permanent adhesive, a semipermanent, a teleporting adhesive, a peelable adhesive or an adhesive in the freezer category. Many of these adhesives can be classified as hot-melt, hot-melt pressure sensitive and pressure sensitive adhesives. Typically, the peelable adhesive is a pressure sensitive adhesive. Examples of such peelable pressure sensitive adhesives are combinations of acrylic, polyurethane, poly-alpha-olefin, silicone, acrylate pressure sensitive adhesives with thermoplastic elastomer-based pressure sensitive adhesives and tacky natural and synthetic rubbers.

The acrylate pressure sensitive adhesive in combination with the thermoplastic elastomer-based pressure sensitive adhesive may be 10 to 90% by weight, or for example 30 to 70% by weight of acrylate pressure sensitive adhesive and 10 to 90% by weight, for example 30 to 70% by weight of thermoplastic elastomer-based pressure sensitive adhesive. Examples of suitable acrylate pressure sensitive adhesives include at least one polymeric monofunctional (meth) acrylic acid ester whose T _g (glass transition temperature) of the polymer is 0 ° C. or lower, and optionally at least one whose T _g of the homopolymer is at least 10 ° C. Derived from copolymerized monofunctional ethylenically unsaturated monomers. The ethylenically unsaturated monofunctional monomer may be present in the acrylate portion of the adhesive in an amount of 5 to 10 weight percent. The thermoplastic elastomer-based pressure sensitive adhesive component may consist of a spinning block copolymer, such as a block copolymer of polystyrene and polybutadiene or polyisoprene or mixtures thereof. Optionally, crosslinkers may be included.

Representative examples of materials suitable for film substrates include polyolefins such as polyethylene, polypropylene and polybutylene, including high density polyethylene, low density polyethylene, linear low density polyethylene and linear ultra low density polyethylene; Vinyl copolymers such as plasticized and unplasticized polyvinyl chloride and polyvinyl acetate; Olefin copolymers such as ethylene / methacrylate copolymers, ethylene / vinyl acetate copolymers, acrylonitrile-butadiene-styrene copolymers and ethylene / propylene copolymers; Acrylic polymers and copolymers; Cellulose; Polyesters and combinations thereof. Any plastic or mixture or blend of plastic and elastomeric materials can be used, for example polypropylene / polyethylene, polyurethane / polyolefin, polyurethane / polycarbonate, polyurethane / polyester.

Such film substrates are opaque to light. This opacity provides improved contrast between the faded and unwashed portions of the patterned composition on the substrate. Typically, such films are white in appearance.

The adhesive portion of the article may have a release release layer that protects the adhesive from the environment and prevents the occurrence of adhesion before the article is applied to the substrate. The release type release layer has a thickness of 1 to 20 mm or for example 5 to 10 mm. Release release layers include, but are not limited to, cellulose, polymers and copolymers such as polyesters, polyurethanes, vinyl copolymers, polyolefins, polycarbonates, polyimides, polyamides, epoxy polymers, and combinations thereof Do not.

The release release layer may comprise a release coating formulation such that the release layer is immediately removable from the adhesive. Such release formulations typically comprise a silicone-vinyl copolymer as the active release agent. Such copolymers are known in the art, and conventional amounts are included in the release layer of the product.

The protective polymer layer may be located on the imaging composition on the film substrate. The protective polymer blocks light to prevent premature activation of the imaging composition on the substrate. The protective polymer layer may be the same material as the substrate.

1 is a cross-sectional view of an example. The product 10 comprises a polyester film base 15 coated on one side with an imaging composition 20. The polyester film base opposite surface is coated with a peelable pressure sensitive adhesive 25. The adhesive coating is protected from the environment by a release release layer 30 comprising a release coating formulation such that the release layer is separated from the pressure sensitive adhesive. The imaging composition is shielded from the environment by an opaque protective polymer layer 35. Such protective polymer layers typically consist of polyethylene. Such polymers are typically used to act as a protective layer for dry film photoresists.

The components constituting the imaging composition can be combined by any suitable method known in the art. Typically, the components are blended or mixed using conventional equipment to form a solid mixture, solution, suspension, dispersion or emulsion. The formulation process is typically performed under a light controlled environment to prevent one or more components from activating prematurely. The composition can then be stored for later use or applied to the substrate immediately by any of the aforementioned methods immediately after formulation. Typically, the composition is stored under a light controlled environment before use. For example, a composition having a sensitizer activated by visible light is typically stored under red light.

Applying a sufficient amount of energy to the imaging composition results in a photoperitive or phototropic response. The amount of energy may be at least 0.2 mJ / cm 2, or for example 0.2 to 100 mJ / cm 2, or for example 2 to 40 mJ / cm 2, or for example 5 to 30 mJ / cm 2.

The imaging composition may be 5 mW or less (ie greater than 0 mW), or 5 mW to 0.01 mW, or 4 mW to 0.05 mW, or 3 mW to 0.1 mW, or 2 mW to 0.25 mW, or 1 mW to 0.5 mW power By changing the color or hue by applying to the energy of. Typically, this power is generated by the visible light source. Other photosensitizers and energy sensitive components that may be included in the imaging composition may change color or hue upon exposure to energy from light other than the visible range. Such photosensitizers and energy sensitive compounds are included to provide more pronounced color or hue contrast as a response caused by the application of energy of up to 5 mW of power. Typically, photosensitizers and energy sensitive compounds that form color or hue contrast by photosensitizers activated by energy of up to 5 mW induce phototropic responses.

While not being bound by theory, it is believed that one or more color or hue changing mechanisms are associated with changing the color or hue after energy application. For example, when a photofugitive response is induced, one or more sensitizers release free radicals to activate one or more reducing agents, which reduce one or more sensitizers to change color or color tone of the composition. Affect When a phototropic response is induced, free radicals, for example from one or more sensitizers, induce a redox reaction between one or more leuco-type compounds and one or more oxidants to change color or color tone. Some formulations have a combination of photoperductive and phototropic responses. For example, exposing the composition to artificial energy, ie, laser light, generates free radicals from one or more sensitizers, which then activates one or more reducing agents to reduce the sensitizer, causing a photoperceptive response and then the same composition. Is exposed to ambient light causing one or more oxidants to oxidize one or more leuco type compounds.

Any suitable energy source can be used to induce photoperductive or phototropic responses. Examples of suitable energy sources include, but are not limited to, lasers, including lasers generated from portable lasers and 3-D imaging systems, and flash lamps. The wavelength of the laser can be manipulated in the range of IR to UV. Two classes of lasers are described that are suitable for changing color or hue.

An excimer laser is a high power laser capable of generating high fluence light in the UV frequency range. Its lasing capacity is based on the excitation of certain biatomic gas molecules. In particular, excimer lasers constitute a family of lasers that emit light in the wavelength range of 157 nm to 355 nm. The most common excimer wavelengths and their respective binary atoms are XeCl (308 nm), KrF (248 nm) and ArF (193 nm). The continuous action in the excimer is the result of the population inversion of the excited dimers formed by the biatomic gas. The pulse width is 10 ns to 100 ns to generate a high energy short pulse width pulse.

Solid state lasers are high power lasers capable of generating focused light beams in the IR to UV wavelength range. Selective portions of these solid-state lasers are based on materials such as yttrium-aluminum garnet (YAG), yttrium-lithium-fluoride (YLF) and yttrium vanadate (YVO ₅ ), and neodymium doping to such a solid host It includes. These materials generate lasers at fundamental wavelengths in the IR range (1.04 to 1.08 microns). Raging can be extended to shorter wavelengths through the use of nonlinear optical crystals such as lithium triborate (LBO) or potassium titanyl phosphate (KTP). As an example, basic 1.06 micron radiation from a neodymium doped YAG laser can use this crystal to increase the frequency to a wavelength of 532 nm.

Examples of other light sources for excimer lasers are short pulse linear excimers, UV flash lamps. Such lamps comprise a transparent quartz lamp tube having an inner diameter of 3 to 20 mm and a wall thickness of 1 mm. The flash lamp can be 30 cm. The electrode made of tungsten is sealed to the end of a lamp tube filled with a rare gas such as xenon. The flash lamp pulses in the range of 1 Hz to 20 Hz by applying a high voltage in the range of 5 KV to 40 KV to the electrode using a capacitor bank. The charge ionizes the xenon atoms to form a plasma that emits broadband radiation in the wavelength range 200 to 800 nm. The flash lamp may include a reflector that is partially disposed around the tube to direct radiation from the lamp to a mask or a work piece.

Linear flash lamps can produce high power, high fluence energy output at short wavelengths of relatively short pulses of 5 μsec. For example, xenon linear flash lamps with broadband spectral output can provide useful energy densities of 1 to 1.5 J / cm 2 for pulses of 2 to 6 μsec.

The imaging composition may be stripped of unwanted portions from the substrate or removed in whole or in part from a substrate using a suitable developer or stripper. The developer and the release agent may be an aqueous base or an organic base. For example, conventional basic aqueous solutions can be used to remove the imaging composition as a polymeric binder with acidic functional groups. Examples of such basic aqueous solutions include alkali metal aqueous solutions such as sodium carbonate and potassium carbonate aqueous solutions. Common organic developers used to remove the composition from the workpiece include, but are not limited to, primary amines such as benzyl, butyl, and allyl amines, secondary amines such as dimethylamine, and tertiary amines such as trimethylamine and triethylamine. It doesn't work.

The product provides a quick and efficient means of changing the color or hue of the workpiece, placing the image on a workpiece such as an aeronautical vessel, marine vessel and earth vehicle, or forming an image on a textile. After applying the product, a sufficient amount of energy is applied to the imaging composition to change its color or hue. In general, color or hue changes are stable. Stabilization means that the color or hue change lasts at least 10 seconds, or 20 minutes to 2 days, or 30 minutes to 1 hour.

Alternatively, energy can be selectively applied to form an imaged pattern, and the workpiece further processed to form the final product. For example, the image can be used as a mark or indicator, for example, to drill holes to tie the connecting parts together, to draft a logo or picture on an airplane, or to align segments of ship parts. Since the product can be quickly applied to the workpiece and the image can be formed quickly by applying energy to form color or tonal contrast, the operator no longer marks the piece with a portable marker or tape during product manufacture. Need not be adjacent to Thus, the laser beam blocking problem caused by the operator using the portable marker or tape is eliminated.

In addition, error reduction by humans increases the accuracy of marking. This is important when the mark is used to specify the alignment of parts, such as aeronautical vessels, marine vessels or earth vehicles, whose accuracy in manufacturing is critical to the reliability and safe operation of the machine. In addition, since pattern formation can be performed using a low power light source (i.e., 5 mW or less), the risk of damaging the eyes of the operator is prevented or at least reduced.

The article is suitable for assembly of industrial assembly lines for many products. For example, a work piece, such as an aircraft body, passes through station 1 where the composition is applied to the surface of the aircraft body to cover the desired portion or entire surface. The product is applied by lamination or manual pressure application. Energy is then applied to the entire surface or selectively applied to move the aircraft body with the product to station 2, which forms an image. When the first aircraft body is in station 2, the second body can be moved to station 1 for product application. Energy can be applied using a laser beam, which causes a change in color or hue on the surface of the aircraft body. Since manual marking by the operator is ruled out, station 3 is then used for further processing, such as developing the imaged aircraft body or stripping unwanted parts of the product, or drilling holes in the fasteners for arrangement of parts at other stations in the body. Move quickly. In addition, the exclusion of the operator from the imaging station improves the accuracy of image formation since there is no operator obstructing the laser beam path to a designated location on the aircraft surface. Thus, the product provides a more efficient manufacturing process than conventional imaging and alignment processes.

In addition to the use of the product in the alignment process, the product can be used to make reinforcement products, photoresists, soldermasks, printing plates, and other photopolymer products.

Imaging compositions can also be used in paints such as aqueous and oil paints. When the composition is used in paint, the composition is included in an amount of 1 to 25%, or 5 to 20%, or 8 to 15% by weight of the final mixture. The imaging composition can be brushed onto a substrate and dried to form a product.

Example 1

Photopergivive and Phototropic Responses

Each component of the two different formulations described in Tables 1 and 2 below were mixed together at 20 ° C. under red light to form a homogeneous mixture. Formulations were prepared to illustrate the difference between the photopergiki response and phototropic response upon exposure to 532 nm.

 ingredient Weight percent  copolymers of n-hexyl methacrylate, methyl methacrylate, n-butyl acrylate, styrene and methacrylic acid 55  Dipropylene glycol dibenzoate 16  Hexaarylbiimidazole 2  9,10-phenanthrequinone 0.2  Triethanolamine triacetate 1.5  Leuco crystal violet 0.3  Cyclopentanone, 2,5-bis [[4- (diethylamino) phenyl] methylene]-, (2E, 5E) 0.1  Methyl ethyl ketone Sufficient amount to make the formulation 100% by weight

Copolymers were formed from monomers of 29 wt% n-hexyl methacrylate, 29 wt% methylmethacrylate, 15 wt% n-butyl acrylate, 5 wt% styrene, and 22 wt% methacrylic acid. Sufficient methyl ethyl ketone was used to form 45 wt% solid mixture. Copolymers were formed by conventional free-radical polymerization.

After preparing a homogeneous mixture, it was spray coated onto a polyethylene film. The polyethylene film was 30 cm x 30 cm and the thickness was 250 microns. The homogeneous mixture was dried using a hair dryer to remove methyl ethyl ketone.

The dry coating on the polyethylene film was reddish brown under UV light as shown in FIG. 2. When the coating was selectively exposed to 532 nm light from a portable laser, a photopergive response was derived. The exposed portion faded in light gray as shown by four rectangular patterns in FIG.

 ingredient Weight percent  copolymers of n-hexyl methacrylate, methyl methacrylate, n-butyl acrylate, styrene and methacrylic acid 64  Dipropylene glycol dibenzoate 19  Fluoride Titanosen 3  Leuco crystal violet One  Methyl ethyl ketone Sufficient amount to make the formulation 100% by weight

The same copolymer as the formulation of Table 1 was used. After the mixture was prepared, it was spray coated onto a polyethylene film under UV light. The polyethylene film was 30 cm x 30 cm and the thickness was 250 microns. The coating on polyethylene was dried using a hair dryer. The coating had a yellowish green appearance under UV light as shown in FIG. 3.

The coating was selectively applied with energy of 532 nm wavelength from the portable laser to induce a phototropic response. The four rectangular patterns formed with the laser darkened to form four purple rectangles as shown in FIG. 3.

Example 2

Photosensitive products

To prepare a composition having the components of Table 3.

 ingredient Weight percent  copolymers of n-hexyl methacrylate, methyl methacrylate, n-butyl acrylate, styrene and methacrylic acid 86  Conjugate Cyclopentanone One  1,6-pyrenquinone 0.5  1,8-pyrenquinone 0.5  Hexaarylbiimidazole 3  Leuco crystal violet 2  Fluoride Onium Salt 3  Secondary amines 2  Triethanolamine triacetate 2  Methyl ethyl ketone Sufficient amount to make the formulation into a 70% by weight solid composition

The copolymer is the same as the copolymer of Example 1. The formulations were prepared at 20 ° C. under red light. The components were mixed using a conventional mixer to form a homogeneous mixture.

The homogeneous mixture was roller coated on one side of a polyethylene terephthalate film having a dimension of 40 cm × 40 cm and a thickness of 2 mm. The opposite side was coated with a 500 micron thick pressure sensitive release adhesive with a peelable protective backside of cellulose acetate. The protective backing has a 50 micron thick silicone vinyl copolymer release layer to facilitate removal of the protective backing from the adhesive. Pressure sensitive release adhesives are conventional polyurethane adhesives.

The coating was dried on a polyethylene terephthalate film with a hair dryer. The peelable cellulose acetate backside was removed and the polyethylene terephthalate film with the coating was hand compressed into an aluminum coupon to a dimension of 60 cm x 60 cm and a thickness of 5 mm. Under UV light the coating appeared amber.

A 532 nm light beam from the portable laser was selectively applied to the amber coating to form five equidistant dot patterns. Selective application of the light beam faded amber to form five distinct dots. A hole was drilled through the aluminum at the dot position using a conventional drill for drilling holes in the aluminum. The polyethylene terephthalate adhesive was peeled off by hand from the aluminum coupon to obtain an aluminum coupon having three equidistant holes.

Example 3

Compositions With Adhesion Enhancers

The compositions in the following table were prepared at 20 ° C. under red light.                     

 ingredient Weight percent  copolymers of n-hexyl methacrylate, methyl methacrylate, n-butyl acrylate, styrene and methacrylic acid 82  Pyrenquinone One   Triethanolamine triacetate 1.5  Leuco crystal violet 0.5  Hexaarylbiimidazole 5  Bisacrylamido acetic acid One  Fluoride Onium Salt 3  Tertiary amine 5  Conjugate Cyclopentanone One  Methyl ethyl ketone Sufficient to make the formulation into a 45% by weight solid composition

The copolymer is the same as the copolymer of Example 1. The components were mixed using a conventional mixer to form a homogeneous mixture.

The homogeneous mixture, along with the cellulose release layer, was roller coated onto a peelable adhesive tape with polyethylene terephthalate at the back. Bisacrylamide acetic acid adhesion promoters are expected to improve the adhesion between the coating and the peelable adhesive tape.

Light was selectively applied at 532 nm with a laser beam so that the coating portion exposed to the light changed from amber to clear color.

Example 4

Photosensitive Compositions in Paint Formulations

The following paint formulations were prepared.                     

 ingredient Weight percent Tamol ^TM 731 (25%) Dispersant One  Propylene glycol 2 Patcote ^TM 801 (Defoamer) One  Titanium Dioxide-Pure R-900 23 Optiwhite ^TM (China Clay) 9 Attagel ^TM 50 (Attapulgite Clay) One  Acrylic polymer binder 32 Texanol ^TM One  Thickener water mixture 21  water Sufficient amount to make the formulation 100% by weight

The paint formulation of Table 5 was blended with the photosensitizer composition of Table 4 of Example 3 so that the photosensitizer composition constituted 5% by weight of the final formulation. The paint and photosensitizer compositions were mixed at 20 ° C. using conventional mixing equipment to form a homogeneous mixture. Mix under red light.

The paint / photosensitive composition mixture was brushed onto a tape having a peelable adhesive and a peelable back side. The composition was air dried at room temperature. The peelable backside was removed and the coating tape was pressed onto an 80 cm x 80 cm and 5 mm thick aluminum coupon. Good adhesion is expected between the mixture and the aluminum coupon.

Light was selectively applied at 532 nm from the portable laser to cause selected portions of the coating to change from amber to clear.

Example 5

Speed comparison test

Two photosensitive compositions were prepared. One composition contained an accelerator as shown in Table 6, and the second composition did not contain an accelerator as shown in Table 7. Each composition was prepared by mixing the components in a conventional laboratory mixer at 20 ° C. under red light.

Photosensitive composition comprising an accelerator  ingredient Weight percent  copolymers of n-hexyl methacrylate, methyl methacrylate, n-butyl acrylate, styrene and methacrylic acid 80  Dipropylene glycol dibenzoate 12  Hexaarylbiimidazole 2  9,10-phenanthrequinone 0.2  Triethanolamine triacetate 1.5  Leuco crystal violet 0.3  Cyclopentanone, 2,5-bis [[4- (diethylamino) phenyl] methylene]-, (2E, 5E)- 0.1  O-phthalic acid 0.4  Fluoride Onium Salt One  Secondary amines 2  Fluid 0.5  Acetone Sufficient amount to make the formulation into a 60% by weight solid composition

Photosensitive composition containing no accelerator  ingredient Weight percent  copolymers of n-hexyl methacrylate, methyl methacrylate, n-butyl acrylate, styrene and methacrylic acid 80  Dipropylene glycol dibenzoate 12  Hexaarylbiimidazole 3  9,10-phenanthrequinone One  Leuco crystal violet 0.5  Cyclopentanone, 2,5-bis [[4- (diethylamino) phenyl] methylene]-, (2E, 5E)- 0.5  O-phthalic acid One  Fluid 2  Acetone Sufficient amount to make the formulation into a 60% by weight solid composition

Each formulation was spray coated onto a separate 60 cm × 60 cm and 5 mm thick aluminum coupon. The acetone solvent was removed from each composition using a hair dryer.

Each coating coupon was selectively exposed to a laser beam having a light beam wavelength of 532 nm. It is expected that a coating with a composition containing an accelerator will change the amber color of the laser light exposure portion to a clear color two to ten times faster than a coating containing no accelerator.

Claims (10)

An article comprising an imaging composition having one or more sensitizers in an amount sufficient to change the color or hue of the imaging composition upon application of energy at a power of 5 mW or less. The composition of claim 1, wherein the imaging composition further comprises one or more reducing agents, color formers, oxidizing agents, binder polymers, plasticizers, flow agents, chain transfer agents, organic acids, adhesion promoters, surfactants, rheology enhancers, thickeners and diluents. product. The product of claim 1 wherein the one or more sensitizers have Formula 1: [Formula 1]

Where p and q are independently 0 or 1, r is 2 or 3, R ₁ is independently hydrogen, linear or branched (C ₁ -C ₁₀ ) alkyl, or linear or branched (C ₁ -C ₁₀ ) alkoxy, R ₂ is independently hydrogen, linear or branched (C ₁ -C ₁₀ ) aliphatic, (C ₅ -C ₇ ) ring, phenyl, alkaryl, linear or branched (C ₁ -C ₁₀ ) hydroxyalkyl, linear or Side chain hydroxy terminating ether, The carbon of each R ₂ is a 5 to 7 membered ring having nitrogen together or a 5 to 7 membered ring having other heteroatoms selected from nitrogen and oxygen, sulfur and a second nitrogen. The article of claim 1, wherein the one or more sensitizers comprise 0.005 to 10 weight percent of the imaging composition. An imaging composition comprising at least one sensitizer on the first side of the substrate, the second side of the substrate comprising an substrate comprising an adhesive, in an amount sufficient to change color or hue upon application of energy at a power of 5 mW or less; product. 6. The product of claim 5, wherein the at least one sensitizer is a conjugated photosensitizer based on cyclopentanone. 6. The article of claim 5, further comprising a protective polymer layer adjacent to the imaging composition. a) providing an imaging composition comprising at least one sensitizer in an amount sufficient to change color or hue upon application of energy at a power of 5 mW or less; b) applying the imaging composition to a substrate to form a product; c) applying energy at a power of 5 mW or less to change color or hue. The method of claim 8, wherein energy is selectively applied to the imaging composition to affect the imaging pattern. The method of claim 8, wherein the amount of energy applied is at least 0.2 mJ / cm 2.

Images